Winches are used in numerous applications to lift or move heavy loads. Common applications include mounting them on tow trucks to pull a disabled vehicle onto the bed of the tow truck or lift one end of the disabled vehicle so that it can be hauled away. Another common application is to mount it on the front or rear end of a vehicle to assist in retrieving the vehicle where it is stuck.
In order to operate a winch it is necessary to be able to pull line off of the spool as well as be able retrieve the line with a load on it. Pulling line off of the spool or paying it out can be done by running the motor backwards such that the spool unwinds the line. While this method will work, it is time consuming, especially if a significant amount of line must be paid out. In these situations it is beneficial to disengage the spool from the drive mechanism. This allows the spool to rotate freely and for the line to be manually pulled off of the spool. Disengaging the spool is typically accomplished by a clutch mechanism. In the past, operation of the clutch mechanism is accomplished through direct manual control of the clutch. This requires the operator to be standing next to the winch and manually operate a gear lever. As can be imagined if the operator is loading a vehicle or moving another type of large load, standing next to the winch may not be the most convenient or safe location.
Various individuals have attempted to incorporate an electronically operated clutch with a winch having a planetary gear drive, also referred to as a planetary winch. This typically involved an electronic solenoid used to overcome a spring or other bias mechanism to move a plunger from an engaged position to a disengaged position (or vise-versa) relative to the ring gear of the planetary gear drive.
The standard solenoid used on these applications required a significant amount of power to move the plunger from one position to the other. Then once moved, the solenoid must remain energized to stay in the moved position and oppose the bias mechanism. This creates a significant drain on the electrical power source. This problem is compounded by the fact most of these winches are used on vehicle of some sort, such as a tow truck, off road vehicle, tractor or the like. This means the electrical power source is a battery with a limited service life. Thus the amount of time the winch can be used is greatly reduced by operation of the electronically actuated clutch. For this very reason electronically operated clutches are not commonly used.
In addition to depleting battery life, the current draw generates a tremendous amount of heat. If the solenoid remains energized for an extended amount of time the heat buildup will lead to failure of the solenoid. Even keeping the solenoid energized for a minute are two can have detrimental effects on the solenoid.
Others in the field have attempted to address this issue by using a solenoid that moves the plunger in one direction with a given polarity of power. The plunger then moves in the opposite direction when the opposite polarity of power is applied. However this is not optimal because of safety concerns. Namely, it is preferred from a safety standpoint to have plunger move to position of having the ring gear locked in place in the event of a power failure. This ensures the load on the winch remains in one place. This feature is not possible where the solenoid is dependent upon a certain polarity of power in order to move it to another position.
What is needed is an apparatus that allows a winch operator to engage and disengage a clutch without standing next to the winch.
Further what is needed is an electronically operated clutch for planetary gear that can operate on a minimum amount of power consumption. Thus avoiding depletion of the battery life and damage arising from the heat generated.
It is also important that the clutch design engages the clutch, that is, it locks the ring gear in place when there is a power failure.